The following description of the background of the invention is provided to aid in understanding the invention, but is not admitted to be or to describe prior art to the invention.
Recently there has been interest in developing devices and methods to systemically deliver pharmaceutical compositions, particularly those comprising a protein or peptide as the prophylactic or therapeutic agent, via or through the lungs of the patient. There are currently three primary device types for the delivery of pharmaceuticals to the respiratory tract.
One such device type is the metered dose inhaler (“MDI”). MDIs use pressurized gas or propellant to deliver a burst of the compound or pharmaceutical into the patient's mouth during inhalation. A second type is the dry powder inhaler (“DPI”). DPIs use a burst of air to draw a dose of inactive powder into the bronchial tract. A third device type is a nebulizer. Nebulizers deliver the pharmaceutical through generating an aerosol by atomizing a liquid.
These conventional device types, however, are not desirable for delivery of certain pharmaceuticals, particularly those intended for systemic administration to the patient. There are many reasons why these conventional devices are not desirable. For example, the precision of dose control and delivery of conventional devices such as MDIs, DPIs, and nebulizers is less accurate for pulmonary delivery, which is of particular concern where specific dosages or dosing regimens are required. Another reason is that pharmaceutical compositions often become attached to or stuck on the side of the device during delivery, thus decreasing the dosage. These devices are also dependent on user technique, which makes dosages variable from person to person and dose to dose.
Thus there is a need to provide devices that are capable of efficient, effective, and consistent delivery of desired dosages of a systemic pharmaceutical to a patient via the pulmonary route.